Plasma processing apparatus

ABSTRACT

A plasma processing apparatus includes: a processing container formed by assembling a container upper portion having an upper side wall and a container lower portion having a lower side wall; a stage provided in the container lower portion of the processing container; and a peripheral introduction part configured to be an assembly, configured to be sandwiched between the upper side wall and the lower side wall, and configured to provide a plurality of gas discharge ports arranged in the circumferential direction with respect to an axis passing through a center of the stage, the assembly in which at least two members are assembled, the at least two members forming a gas flow path extending in a circumferential direction with respect to the axis in an interior thereof, in which the peripheral introduction part, the container upper portion and the container lower portion are thermally and electrically connected to each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims the benefit of priority fromJapanese Patent Application No. 2018-049470 filed on Mar. 16, 2018, andthe entire contents of which are incorporated herein by reference.

FIELD

Exemplary embodiments of the disclosure relates to a plasma processingapparatus.

BACKGROUND

In the manufacture of electronic devices, plasma processing such asplasma etching is applied to an object to be processed. JapaneseUnexamined Patent Publication No. 2014-096553 discloses a plasmaprocessing apparatus for performing plasma processing on an object to beprocessed. The plasma processing apparatus disclosed in JapaneseUnexamined Patent Publication No. 2014-096553 is a plasma processingapparatus which generates plasma by microwaves, and includes a stage, acentral introduction part, and a peripheral introduction part. Theobject to be processed is placed on the stage. The central introductionpart introduces gas from above the stage along an axis passing throughthe center of the stage in a vertical direction. Further, the peripheralintroduction part is formed of a ring-shaped member having a gas flowpath formed in the interior thereof and is provided along a side wall ata height position between a gas discharge port of the centralintroduction part and the stage. A plurality of gas discharge portsarranged in a circumferential direction are formed in the peripheralintroduction part. A pipe communicating with the gas flow path in theinterior of the peripheral introduction part is connected to theperipheral introduction part. A connection place between the peripheralintroduction part and the pipe is fixed such that the peripheralintroduction part and the pipe are not separated from each other.Specifically, a gas introduction portion of the peripheral introductionpart and a tip portion of the pipe are fixed to the side wall of theprocessing container by a fixing member.

SUMMARY

In first aspect, a plasma processing apparatus includes: a processingcontainer formed by assembling a container upper portion having an upperside wall and a container lower portion having a lower side wall; astage provided in the container lower portion of the processingcontainer; and a peripheral introduction part configured to be anassembly, configured to be sandwiched between the upper side wall andthe lower side wall, and configured to provide a plurality of gasdischarge ports arranged in the circumferential direction with respectto an axis passing through a center of the stage, the assembly in whichat least two members are assembled, the at least two members forming agas flow path extending in a circumferential direction with respect tothe axis in an interior thereof, in which the peripheral introductionpart, the container upper portion and the container lower portion arethermally and electrically connected to each other.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, exemplaryembodiments, and features described above, further aspects, exemplaryembodiments, and features will become apparent by reference to thedrawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view schematically illustrating a plasmaprocessing apparatus according to an exemplary embodiment.

FIG. 2 is a plan view illustrating an example of a slot plate.

FIG. 3 is a plan view illustrating an example of a dielectric window.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3.

FIG. 5 is a plan view illustrating a state where the slot plateillustrated in FIG. 2 is provided on the dielectric window illustratedin FIG. 3.

FIG. 6 is a sectional perspective view illustrating an example of aprocessing container.

FIG. 7 is a perspective view illustrating an example of a peripheralintroduction part.

FIG. 8 is an exploded view illustrating an example of the peripheralintroduction part.

FIG. 9 is a sectional perspective view illustrating an example of theperipheral introduction part and a gas supply block.

FIG. 10 is a sectional view illustrating an example of a state where theperipheral introduction part is mounted.

FIG. 11 is a sectional view illustrating an example of a state where theperipheral introduction part is mounted.

FIG. 12 is a partial sectional view illustrating an example of a gasdischarge port of the peripheral introduction part.

FIG. 13 is a sectional perspective view illustrating an example ofassembly of the peripheral introduction part.

FIG. 14 is a sectional perspective view illustrating an example ofassembly of the peripheral introduction part.

FIGS. 15A and 15B are sectional views for describing an example of apushing screw mechanism for disconnecting connection between a containerupper portion and the peripheral introduction part.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. The exemplaryembodiments described in the detailed description, drawing, and claimsare not meant to be limiting. Other exemplary embodiments may beutilized, and other changes may be made, without departing from thespirit or scope of the subject matter presented here.

In the plasma processing apparatus disclosed in Japanese UnexaminedPatent Publication No. 2014-096553, the ring-shaped peripheralintroduction part rises in temperature due to plasma heat or the like.The ring-shaped peripheral introduction part thermally expands in aradial direction according to a rise in temperature. Since theconnection place between the ring-shaped peripheral introduction partand the pipe serves as a fixed end, there is a concern that thering-shaped peripheral introduction part may not expand equally in theradial direction. In this case, since the axis passing through thecenter of the stage and the axis passing through the center of thering-shaped peripheral introduction part are shifted from each other,there is a concern that bias may occur in the distribution of gas. Thatis, there is a concern that the uniformity of the plasma processing onthe object to be processed may be reduced.

Further, it is necessary to periodically clean the peripheralintroduction part. Since the peripheral introduction part described inJapanese Unexamined Patent Publication No. 2014-096553 is a ring-shapedmember in which a gas flow path is formed in the interior thereof,cleaning work is not easy.

Therefore, in the plasma processing apparatus, it is necessary tosuppress a decrease in uniformity of plasma processing due to thermalexpansion of the peripheral introduction part and improvemaintainability of the peripheral introduction part.

According to one aspect, a plasma processing apparatus for performingplasma processing on an object to be processed is provided. The plasmaprocessing apparatus includes a processing container, a stage, and aperipheral introduction part. The processing container is formed byassembling a container upper portion having an upper side wall and acontainer lower portion having a lower side wall. The stage is providedin the container lower portion of the processing container. Theperipheral introduction part is an assembly in which at least twomembers are assembled, so that a gas flow path extending in acircumferential direction with respect to an axis passing through acenter of the stage is formed in an interior thereof. The peripheralintroduction part is sandwiched between the upper side wall and thelower side wall and provides a plurality of gas discharge ports arrangedin the circumferential direction with respect to the axis. Theperipheral introduction part, and the container upper portion and thecontainer lower portion are thermally and electrically connected to eachother.

According to this plasma processing apparatus, since the peripheralintroduction part is an assembly, the interior of the gas flow path canbe cleaned by releasing the coupling between at least two membersforming the gas flow path. Further, according to this plasma processingapparatus, since the ring-shaped peripheral introduction part is fixedby being sandwiched between the upper side wall and the lower side wall,it can thermally expand uniformly in the circumferential direction. Forthis reason, in this plasma processing apparatus, it is possible toavoid positional misalignment between the axis passing through thecenter of the stage and the axis passing through the center of thering-shaped peripheral introduction part. Therefore, in this plasmaprocessing apparatus, it is possible to suppress a decrease in theuniformity of the plasma processing due to the thermal expansion of theperipheral introduction part and to improve the maintainability of theperipheral introduction part.

In one aspect, the at least two members may include a first ring memberand a second ring member, and the gas flow path may be formed byassembling the first ring member and the second ring member. In thiscase, in this plasma processing apparatus, the entire interior of thegas flow path can be opened by releasing the coupling between the firstring member and the second ring member. Therefore, in this plasmaprocessing apparatus, the maintainability can be further improved.

In one aspect, the container lower portion and the second ring membermay be positioned by a first pin extending along the axis, and thesecond ring member, the first ring member, and the container upperportion may be positioned by a second pin extending along the axis. Inthis case, in this plasma processing apparatus, positioning of thecontainer upper portion, the first ring member, the second ring member,and the container lower portion can be performed by the first pin andthe second pin.

In one aspect, the peripheral introduction part, the container upperportion, and the container lower portion may be formed of the samematerial. In this case, the thermal expansion coefficients of theperipheral introduction part, the container upper portion, and thecontainer lower portion become the same. Therefore, in this plasmaprocessing apparatus, the axis passing through the center of the stageand the axis passing through the center of the ring-shaped peripheralintroduction part can be prevented from being shifted from each otherdue to the difference in thermal expansion between the processingcontainer and the peripheral introduction part.

In one aspect, the peripheral introduction part, the container upperportion, and the container lower portion may be formed of aluminum.

In one aspect, an aluminum oxide film may be formed on an inner wall ofthe gas flow path, and the gas discharge port may communicate with acorner portion of a cross-section of the gas flow path. The aluminumoxide film is formed by alumite treatment. At the time of the alumitetreatment, air pockets tend to be formed at the corner portion of thecross-section of the gas flow path. In this plasma processing apparatus,the gas discharge port is formed at the corner portion of thecross-section of the gas flow path, so that it is possible to preventthe air pockets from staying in the corner portion.

In one aspect, the plasma processing apparatus may further include acentral introduction part which is provided above the stage andintroduces gas toward the stage along the axis, and an antenna forintroducing microwaves into the processing container. The antenna may beprovided to face the stage above the stage and have a dielectric windowwhich is in contact with a space in the processing container. A gasdischarge port of the central introduction part, which extends along theaxis, may be formed in the dielectric window. According to this plasmaprocessing apparatus, gas can also be supplied from the centralintroduction part and plasma can be excited by using the antenna.

As described above, the plasma processing apparatus is provided in whicha decrease in uniformity of plasma processing due to thermal expansionof the peripheral introduction part is suppressed and maintainability ofthe peripheral introduction part is improved.

Hereinafter, various exemplary embodiments will be described in detailwith reference to the drawings. In each drawing, identical orcorresponding portions are denoted by the same reference numerals.

[Outline of Plasma Processing Apparatus]

FIG. 1 is a sectional view schematically illustrating a plasmaprocessing apparatus according to an exemplary embodiment. A plasmaprocessing apparatus 10 illustrated in FIG. 1 is an apparatus forperforming plasma processing on an object to be processed. The plasmaprocessing apparatus is provided with a processing container 12. Theprocessing container 12 provides a processing space S for accommodatingthe object to be processed. An example of the object to be processed isa wafer W.

The processing container 12 is formed by assembling a container upperportion 12A having an upper side wall 12 a and a container lower portion12B having a lower side wall 12 b. The assembly of the container upperportion 12A and the container lower portion 12B will be described later.The processing container 12 has a side wall which includes the upperside wall 12 a and the lower side wall 12 b. The processing container 12can further include a bottom portion 12 c and a top portion 12 d. Eachof the upper side wall 12 a and the lower side wall 12 b has asubstantially cylindrical shape extending in a direction in which anaxis Z extends. The axis Z is, for example, an axis which passes throughthe center of a stage (described later) in a vertical direction. In oneexemplary embodiment, the central axes of the upper side wall 12 a andthe lower side wall 12 b coincide with the axis Z. The inner diameter ofeach of the upper side wall 12 a and the lower side wall 12 b is, forexample, 540 mm.

The bottom portion 12 c is provided on the lower end side of the lowerside wall 12 b. Further, an upper end portion of the upper side wall 12a is open. The upper end opening of the upper side wall 12 a is closedby a dielectric window 18. The dielectric window 18 is sandwichedbetween the upper end portion of the upper side wall 12 a and the topportion 12 d. A sealing member SL1 may be interposed between thedielectric window 18 and the upper end portion of the upper side wall 12a. The sealing member SL1 is, for example, an O-ring and contributes tothe hermetic sealing of the processing container 12. The container upperportion 12A and the container lower portion 12B can be formed of, forexample, aluminum.

The plasma processing apparatus 10 further includes a stage 20 providedin the container lower portion 12B of the processing container 12. Thestage 20 is provided below the dielectric window 18. For example, thedistance between the lower surface of the dielectric window 18 and theupper surface of the stage 20 is 245 mm. In one exemplary embodiment,the stage 20 includes a lower electrode LE and an electrostatic chuckESC.

The lower electrode LE includes a first plate 22 a and a second plate 22b. Both the first plate 22 a and the second plate 22 b have asubstantially disk shape and are made of, for example, aluminum. Thefirst plate 22 a is supported by a tubular support part SP1. The supportpart SP1 extends vertically upward from the bottom portion 12 c. Thesecond plate 22 b is provided on the first plate 22 a and electricallyconnected to the first plate 22 a.

The lower electrode LE is electrically connected to a radio-frequencypower source RFG through a power supply rod PFR and a matching unit MU.The radio-frequency power source RFG supplies radio-frequency bias powerto the lower electrode LE. The radio-frequency bias power which isgenerated by the radio-frequency power source RFG can have a certainfrequency, for example, a frequency of 13.65 MHz, which is suitable forcontrolling the energy of ions which are drawn into the wafer W. Thematching unit MU accommodates a matching device for performing matchingbetween impedance on the radio-frequency power source RFG side andimpedance on the load side such as mainly the electrode, plasma, and theprocessing container 12. For example, a blocking capacitor for self-biasgeneration can be included in the matching device.

The electrostatic chuck ESC is provided on the second plate 22 b. Theelectrostatic chuck ESC provides a placing region MR for placing thewafer W on the processing space S side. The placing region MR is asubstantially circular region substantially orthogonal to the axis Z andcan have a diameter approximately equal to the diameter of the wafer Wor a diameter slightly smaller than the diameter of the wafer W.Further, the placing region MR configures the upper surface of the stage20, and the center of the placing region MR, that is, the center of thestage 20 is located on the axis Z.

The electrostatic chuck ESC holds the wafer W by an electrostaticattraction force. The electrostatic chuck ESC includes an attractionelectrode provided in a dielectric. A direct-current power supply DCS isconnected to the attraction electrode of the electrostatic chuck ESCthrough a switch SW and a covered wire CL. The electrostatic chuck ESCcan hold the wafer W by attracting the wafer W to the upper surfacethereof by a Coulomb force which is generated by a direct-currentvoltage which is applied from the direct-current power supply DCS. Afocus ring FR annularly surrounding the periphery of the wafer W isprovided on the outside in a radial direction of the electrostatic chuckESC.

An annular flow path 24 g is formed in the interior of the second plate22 b. A refrigerant is supplied to the flow path 24 g from a chillerunit through a pipe PP1. The refrigerant supplied to the flow path 24 gis recovered to the chiller unit through a pipe PP3. Further, in theplasma processing apparatus 10, a heat transfer gas, for example, Hegas, from a heat transfer gas supply unit is supplied between the uppersurface of the electrostatic chuck ESC and the back surface of the waferW through a supply pipe PP2.

A space is provided outside the outer periphery of the stage 20, thatis, between the stage 20 and the lower side wall 12 b. The space servesas an exhaust path VL having an annular shape when viewed in a planview. An annular baffle plate 26 having a plurality of through-holes isprovided in the middle of the exhaust path VL in the direction of theaxial Z. The exhaust path VL is connected to an exhaust pipe 28 whichprovides an exhaust port 28 h. The exhaust pipe 28 is mounted to thebottom portion 12 c of the processing container 12. An exhaust device 30is connected to the exhaust pipe 28. The exhaust device 30 has apressure regulator and a vacuum pump such as a turbo-molecular pump. Theexhaust device 30 can reduce the pressure in the processing space S inthe processing container 12 to a desired degree of vacuum. Further, thegas supplied to the wafer W flows toward the outside of the edge of thewafer W along the surface of the wafer W by operating the exhaust device30 and is exhausted from the outer periphery of the stage 20 through theexhaust path VL.

In one exemplary embodiment, the plasma processing apparatus 10 canfurther include heaters HT, HS, HC, and HE as temperature controlmechanisms. The heater HT is provided in the top portion 12 d andextends in an annular shape to surround an antenna 14. The heater HS isprovided in the upper side wall 12 a and extends in an annular shape.The heater HS may be further provided in the lower side wall 12 b. Theheater HC is provided in the second plate 22 b or in the electrostaticchuck ESC. The heater HC is provided below a central portion of theplacing region MR described above, that is, in a region crossing theaxis Z. Further, the heater HE extends in an annular shape to surroundthe heater HC. The heater HE is provided below an outer edge portion ofthe placing region MR described above.

In one exemplary embodiment, the plasma processing apparatus 10 canfurther include the antenna 14, a coaxial waveguide 16, a microwavegenerator 32, a tuner 34, a waveguide 36, and a mode converter 38. Theantenna 14, the coaxial waveguide 16, the dielectric window 18, themicrowave generator 32, the tuner 34, the waveguide 36, and the modeconverter 38 configure a plasma generation source for exciting the gaswhich is introduced into the processing container.

The microwave generator 32 generates microwaves having a frequency of,for example, 2.45 GHz. The microwave generator 32 is connected to anupper portion of the coaxial waveguide 16 through the tuner 34, thewaveguide 36, and the mode converter 38. The coaxial waveguide 16extends along the axis Z which is a central axis thereof.

The coaxial waveguide 16 includes an outer conductor 16 a and an innerconductor 16 b. The outer conductor 16 a has a cylindrical shapeextending with the axis Z as the center. A lower end of the outerconductor 16 a is electrically connected to an upper portion of acooling jacket 40 having an electrically conductive surface. The innerconductor 16 b is provided coaxially with the outer conductor 16 ainside the outer conductor 16 a. The inner conductor 16 b has acylindrical shape extending with the axis Z as the center. A lower endof the inner conductor 16 b is connected to a slot plate 44 of theantenna 14.

The antenna 14 introduces microwaves into the processing container 12.The antenna 14 is provided to face the stage 20 above the stage 20. Theantenna 14 is disposed in an opening formed in the top portion 12 d. Theantenna 14 includes a dielectric plate 42, the slot plate 44, and thedielectric window 18. The dielectric plate 42 shortens the wavelength ofthe microwave. The dielectric plate 42 has a substantially disk shape.The dielectric plate 42 is made of, for example, quartz or alumina. Thedielectric plate 42 is sandwiched between the slot plate 44 and thelower surface of the cooling jacket 40. An example of the antenna 14 isa radial line slot antenna.

FIG. 2 is a plan view illustrating an example of the slot plate. Theslot plate 44 has the form of a thin plate and has a disk shape. Bothsurfaces of the slot plate 44 in a plate thickness direction thereof areflat. A center CS of the slot plate 44 is located on the axis Z. Aplurality of slot pairs 44 p are provided in the slot plate 44. Each ofthe plurality of slot pairs 44 p includes two slot holes 44 a and 44 bpenetrating in the plate thickness direction. The planar shape of eachof the slot holes 44 a and 44 b is an elongated hole shape. In each ofthe slot pairs 44 p, a direction in which the major axis of the slothole 44 a extends and a direction in which the major axis of the slothole 44 b extends cross each other or are orthogonal to each other. Theplurality of slot pairs 44 p are arranged in a circumferentialdirection. In the example illustrated in FIG. 2, the plurality of slotpairs 44 p are arranged in the circumferential direction along twoconcentric circles. On each concentric circle, the slot pairs 44 p arearranged at approximately equal intervals. The slot plate 44 is providedon an upper surface 18 u of the dielectric window 18.

FIG. 3 is a plan view illustrating an example of the dielectric window,and FIG. 4 is a sectional view taken along line IV-IV of FIG. 3. Asillustrated in FIGS. 3 and 4, the dielectric window 18 is asubstantially disk-shaped member made of a dielectric such as quartz. Athrough-hole 18 h is formed at the center of the dielectric window 18.An upper portion of the through-hole 18 h is a space 18 s in which aninjector 50 b of a central introduction part 50 (described later) isaccommodated, and a lower portion of the through-hole 18 h is a gasdischarge port 18 i of the central introduction part 50 (describedlater). The center axis of the dielectric window 18 coincides with theaxis Z.

The surface on the side opposite to the upper surface 18 u of thedielectric window, that is, a lower surface 18 b is in contact with theprocessing space S and is a surface on the side where plasma isgenerated. The lower surface 18 b has various shapes. Specifically, thelower surface 18 b has a flat surface 180 defined at the central regionsurrounding the gas discharge port 18 i. The flat surface 180 is a flatsurface orthogonal to the axis Z. The lower surface 18 b has a firstrecessed portion 181 having an annular shape. The first recessed portion181 is formed in an annular shape at a region on the outside in theradial direction of the flat surface 180 and is recessed in a taperedshape toward the inner side in the plate thickness direction of thedielectric window 18.

Further, the lower surface 18 b has a plurality of second recessedportions 182. The plurality of second recessed portions 182 are recessedtoward the inner side in the plate thickness direction from the flatsurface 180. The number of the plurality of second recessed portions 182is seven in the example illustrated in FIGS. 3 and 4. The plurality ofsecond recessed portions 182 are formed at equal intervals along thecircumferential direction. Further, the plurality of second recessedportions 182 have a circular planar shape in a plane orthogonal to theaxis Z.

FIG. 5 is a plan view illustrating a state where the slot plateillustrated in FIG. 2 is provided on the dielectric window illustratedin FIG. 3, and illustrate the state when the dielectric window 18 isviewed from the lower side. As illustrated in FIG. 5, when viewed in aplan view, that is, in a case of being viewed in the direction of theaxis Z, the slot pairs 44 p provided along the concentric circle on theouter side in the radial direction overlap the first recessed portion181. Further, the slot holes 44 b of the slot pairs 44 p provided alongthe concentric circle on the inner side in the radial direction overlapthe first recessed portion 181. In addition, the slot holes 44 a of theslot pairs 44 p provided along the concentric circle on the inner sidein the radial direction respectively overlap the plurality of secondrecessed portions 182.

Referring to FIG. 1 again, in the plasma processing apparatus 10, themicrowaves generated by the microwave generator 32 are propagated to thedielectric plate 42 through the coaxial waveguide 16 and applied to thedielectric window 18 from the slot holes 44 a and 44 b of the slot plate44. Just below the dielectric window 18, the energy of the microwavesconcentrates in the first recessed portion 181 and the second recessedportions 182 defined by the portions having a relatively thin platethickness. Therefore, the plasma processing apparatus 10 can generateplasma such that the plasma is stably distributed in the circumferentialdirection and the radial direction.

In one exemplary embodiment, the plasma processing apparatus 10 includesthe central introduction part 50. The central introduction part 50 isprovided above the stage 20. The central introduction part 50 introducesgas toward the stage 20 along the axis Z. The central introduction part50 includes a conduit 50 a, the injector 50 b, and the gas dischargeport 18 i. The conduit 50 a passes through the inner hole of the innerconductor 16 b of the coaxial waveguide 16. An end portion of theconduit 50 a extends to the space 18 s (refer to FIG. 4) defined in thedielectric window 18 along the axis Z. The injector 50 b is accommodatedin the space 18 s and below the end portion of the conduit 50 a. Aplurality of through-holes extending in the direction of the axis Z areprovided in the injector 50 b. Further, the dielectric window 18provides the gas discharge port 18 i described above. The gas dischargeport 18 i is continuous below the space 18 s and extends along the axisZ. The central introduction part 50 having such a configuration suppliesgas to the injector 50 b through the conduit 50 a and discharges the gasfrom the injector 50 b through the gas discharge port 18 i. In thismanner, the central introduction part 50 discharges the gas to justbelow the dielectric window 18 along the axis Z. That is, the centralintroduction part 50 introduces the gas into a plasma generation areahaving a high electron temperature. Further, the gas discharged from thecentral introduction part 50 flows toward the central region of thewafer W substantially along the axis Z.

A first gas source group GSG1 is connected to the central introductionpart 50 through a first flow rate control unit group FCG1. The first gassource group GSG1 includes a plurality of first gas sources. Theplurality of first gas sources are sources of various gases necessaryfor the processing of the wafer W. Such a gas can include a corrosivegas such as HBr gas in a case of etching a polycrystalline siliconlayer. Further, the gas can include various gases such as a rare gassuch as Ar or He, or an oxygen gas. The first flow rate control unitgroup FCG1 includes a plurality of flow rate controllers and a pluralityof on-off valves. Each of the first gas sources is connected to thecentral introduction part 50 through a corresponding flow controller andon-off valve of the first flow rate control unit group FCG1.

The plasma processing apparatus 10 includes a peripheral introductionpart 52. The peripheral introduction part 52 is provided in theprocessing container 12 by being sandwiched between the upper side wall12 a and the lower side wall 12 b. For this reason, the peripheralintroduction part 52 configures a part of the side wall of theprocessing container 12. The peripheral introduction part 52 is providedbetween the gas discharge port 18 i of the central introduction part 50and the upper surface of the stage 20 in the height direction, that is,the direction of the axis Z.

FIG. 6 is a sectional perspective view illustrating an example of theprocessing container. As illustrated in FIG. 6, the peripheralintroduction part 52 provides a plurality of gas discharge ports 52 iarranged in the circumferential direction with respect to the axis Z.The plurality of gas discharge ports 52 i introduce gas into theprocessing space S from positions along the side wall of the processingcontainer 12. The peripheral introduction part 52 configures an annularpipe in which the plurality of gas discharge ports 52 i are formed. Agas flow path 52 p extending in the circumferential direction withrespect to the axis Z is formed in the interior of the peripheralintroduction part 52. The peripheral introduction part 52 is disposed,for example, at a distance of 90 mm upward from the upper surface of thestage 20. The peripheral introduction part 52 can be formed of, forexample, aluminum.

Each of the plurality of gas discharge ports 52 i extends such that thegas discharge port 52 i becomes more distant from the upper surface ofthe stage 20 as it comes close to the axis Z. In other words, each ofthe plurality of gas discharge ports 52 i extends in a direction havinga component toward the center of the processing space S and a componentaway from the stage 20 along the axis Z, that is, extends obliquelyupward. In a case of assuming an imaginary plane orthogonal to the axisZ, the center line of each gas discharge port 52 i forms an angle withrespect to the imaginary plane. This angle can have an angle of 30degrees or more and 45 degrees or less.

A second gas source group GSG2 (refer to FIG. 1) is connected to theannular gas flow path 52 p of the peripheral introduction part 52through a gas supply block 62 and a second flow rate control unit groupFCG2 (refer to FIG. 1). The second gas source group GSG2 includes aplurality of second gas sources. The plurality of second gas sources aresources of various gases necessary for the processing of the wafer W.Such a gas can include a corrosive gas such as HBr gas in a case ofetching a polycrystalline silicon layer. Further, the gas can includevarious gases such as a rare gas such as Ar or He, or an oxygen gas. Thesecond flow rate control unit group FCG2 includes a plurality of flowrate controllers and a plurality of on-off valves. Each of the secondgas sources is connected to the peripheral introduction part 52 througha corresponding flow rate controller and on-off valve of the second flowrate control unit group FCG2.

The plasma processing apparatus 10 can independently control the type ofthe gas which is introduced into the processing space S from the centralintroduction part 50 and the flow rate of one or more gases which areintroduced into the processing space S from the central introductionpart 50, and also independently controls the type of gas which isintroduced into the processing space S from the peripheral introductionpart 52 and the flow rate of one or more gases which are introduced intothe processing space S from the peripheral introduction part 52.

Further, the gas introduced from the peripheral introduction part 52flows obliquely upward in the processing space S and merges with the gaswhich is introduced from the central introduction part 50, or flowsalong the flow of the gas which is introduced from the centralintroduction part 50. Therefore, on the wafer W placed on the stage 20,the gas flows in the direction toward the edge of the wafer W from thecenter of the wafer W. Therefore, a stay of the gas on the wafer W issuppressed. As a result, the in-plane uniformity of the processing ofthe wafer W is improved.

In one exemplary embodiment, the plasma processing apparatus 10 canfurther include a control unit Cnt, as illustrated in FIG. 1. Thecontrol unit Cnt can be a controller such as a programmable computerdevice. The control unit Cnt can control each part of the plasmaprocessing apparatus 10 according to a recipe-based program. Forexample, the control unit Cnt can send a control signal to the flow ratecontroller and the on-off valve of the first flow rate control unitgroup FCG1 to adjust the gaseous species and the flow rate of the gaswhich is introduced from the central introduction part 50. The controlunit Cnt can send a control signal to the flow rate controller and theon-off valve of the second flow rate control unit group FCG2 to adjustthe gaseous species and the flow rate of the gas which is introducedfrom the peripheral introduction part 52. The control unit Cnt cansupply control signals to the microwave generator 32, theradio-frequency power source RFG, and the exhaust device 30 to controlthe power of the microwave, the power and ON/OFF of the radio-frequencybias power, and the pressure in the processing container 12. Further,the control unit Cnt can send a control signal to the heater powersupply connected to the heaters HT, HS, HC, and HE to adjust thetemperatures of these heaters.

A plasma processing method which is carried out using the plasmaprocessing apparatus 10 described above will be described. In thismethod, first, the wafer W is prepared. Specifically, the wafer W isplaced on the stage 20 and attracted to the stage 20 by theelectrostatic chuck ESC. Then, the exhaust device 30 is operated,whereby the pressure in the space inside the processing container 12 isset to a predetermined pressure. Subsequently, gases are introduced intothe processing container 12 from the central introduction part 50 andthe peripheral introduction part 52. Subsequently, plasma of the gasesintroduced into the processing container 12 is generated. The wafer W isprocessed by the plasma of the gases.

[Details of Peripheral Introduction Part]

FIG. 7 is a perspective view illustrating an example of the peripheralintroduction part. FIG. 8 is an exploded view illustrating an example ofthe peripheral introduction part. FIG. 9 is a sectional perspective viewillustrating an example of the peripheral introduction part and the gassupply block. As illustrated in FIGS. 7 to 9, the peripheralintroduction part 52 is an assembly in which at least two members areassembled. The at least two members can include a first ring member 52 aand a second ring member 52 b. Each of the first ring member 52 a andthe second ring member 52 b is an annular member. The first ring member52 a and the second ring member 52 b are assembled, whereby an annularpipe member is configured, and the gas flow path 52 p is formed in theinterior of the annular pipe member. As an example, the first ringmember 52 a defines the inner surface on the inner side in the radialdirection of the gas flow path 52 p, and the second ring member 52 bdefines the inner surface on the outer side in the radial direction ofthe gas flow path 52 p.

As a more specific example, the first ring member 52 a has a first base52 m, a first side portion 52 n, and a first bottom portion 52 r. Thefirst base 52 m is a flat portion having a ring shape and defines aceiling of the gas flow path 52 p at the lower surface thereof. Thefirst side portion 52 n is provided to be erected downward at an endportion on the inner side of the first base 52 m and defines the sidesurface of the gas flow path 52 p at the outer surface thereof. That is,the first side portion 52 n defines an inner side surface that is closerto the axis Z, out of two side surfaces of the gas flow path 52 p. Thefirst bottom portion 52 r is provided to be erected from a lower endportion of the first side portion 52 n toward the outer side of thefirst base 52 m and defines the bottom surface of the gas flow path 52 pat the upper surface thereof. In this manner, the first ring member 52 adefines the ceiling, the inner side surface, and the bottom surfaceamong the inner surfaces of the gas flow path 52 p. The first ringmember 52 a is formed of, for example, aluminum.

As an example, the second ring member 52 b has a second base 52 x and astepped portion 52 y. The second base 52 x is a ring-shaped portionhaving a larger thickness than the gas flow path 52 p and defines theside surface of the gas flow path 52 p at the side surface on the innerside thereof. That is, the second base 52 x defines an outer sidesurface that is farther from the axis Z, out of the two side surfaces ofthe gas flow path 52 p. The stepped portion 52 y is a portion protrudinginward in the radial direction at the lower end portion on the innerside of the second ring member 52 b. The second ring member 52 b isformed of, for example, aluminum.

The first ring member 52 a and the second ring member 52 b areassembled, whereby the lower surface of the first base 52 m of the firstring member 52 a is supported in a state of being in contact with theupper surface of the second base 52 x of the second ring member 52 b.The lower surface of the first bottom portion 52 r of the first ringmember 52 a is supported on the upper surface of the stepped portion 52y of the second ring member 52 b. The first ring member 52 a and thesecond ring member 52 b are fixed to each other by screws in theassembled state. In the illustrated example, five screws are screwed toscrew holes provided in the first ring member 52 a and the second ringmember 52 b.

A sealing member 54 a such as an O-ring may be provided between thelower surface of the first base 52 m of the first ring member 52 a andthe upper surface of the second base 52 x of the second ring member 52b. For example, the sealing member 54 a is an annular member and isaccommodated in an annular groove formed on the upper surface of thesecond base 52 x. A sealing member 54 b such as an O-ring may beprovided between the lower surface of the first bottom portion 52 r ofthe first ring member 52 a and the upper surface of the stepped portion52 y of the second ring member 52 b. For example, the sealing member 54b is an annular member and is accommodated in an annular groove formedon the upper surface of the stepped portion 52 y. Due to the sealingmembers 54 a and 54 b, the airtightness between the first ring member 52a and the second ring member 52 b is secured.

An electrically conductive member 55 a may be provided between the lowersurface of the first base 52 m of the first ring member 52 a and theupper surface of the second base 52 x of the second ring member 52 b. Asan example, the electrically conductive member 55 a is an annularstring-like member in which a thin metal is spirally wound. For example,the electrically conductive member 55 a is accommodated in an annulargroove formed on the upper surface of the second base 52 x. Due to theelectrically conductive member 55 a, the conductivity between the firstring member 52 a and the second ring member 52 b is improved.

A cover portion 52 k protruding downward may be formed at the lower endportion on the inner side of the first bottom portion 52 r of the firstring member 52 a. The cover portion 52 k extends further downward on theinner side in the radial direction than the connection surface betweenthe lower surface of the first bottom portion 52 r of the first ringmember 52 a and the upper surface of the stepped portion 52 y of thesecond ring member 52 b at the time of assembly. The cover portion 52 kcovers the connection surface between the lower surface of the firstbottom portion 52 r of the first ring member 52 a and the upper surfaceof the stepped portion 52 y of the second ring member 52 b such that theconnection surface does not directly face plasma. In this way, plasma orions cannot reach the connection surface unless the gap formed betweenthe cover portion 52 k and the second ring member 52 b is increased. Byproviding the cover portion 52 k, it is possible to suppress theshortening of the life of the sealing member 54 b.

A fixed block 53 a is fixed to the side surface of the second ringmember 52 b by screws. The fixed block 53 a is a part of a pushing screwmechanism which disconnects the connection between the container upperportion 12A and the peripheral introduction part 52. Details thereofwill be described later.

A connection surface 52 e for connecting the gas supply block 62 isformed on the side surface of the second ring member 52 b. A gasintroduction port 52 g communicating with the gas flow path 52 p isformed on the connection surface 52 e. The gas supply block 62 is fixedto the connection surface 52 e of the second ring member 52 b by screws.The gas supply block 62 has a gas output port 62 a for outputting thegas supplied from the second gas source group GSG2 (refer to FIG. 1).The gas supply block 62 is positioned and fixed such that the gas outputport 62 a is aligned with the gas introduction port 52 g of the secondring member 52 b. A sealing member 54 c such as an O-ring may beprovided between the gas supply block 62 and the second ring member 52b. For example, the sealing member 54 c is an annular member and isaccommodated in an annular groove formed on the connection surface ofthe gas supply block 62 to surround the gas output port 62 a. Due to thesealing member 54 c, the airtightness between the gas supply block 62and the second ring member 52 b is secured. The second ring member 52 bhas an intermediate flow path 52 h connecting the gas introduction port52 g and the gas flow path 52 p. The gas supplied from the second gassource group GSG2 passes through the gas output port 62 a of the gassupply block 62, the gas introduction port 52 g, and the intermediateflow path 52 h and is supplied to the gas flow path 52 p.

FIGS. 10 and 11 are sectional views illustrating an example of the statewhere the peripheral introduction part is mounted. FIG. 10 is asectional view of a connection place with the gas supply block 62, andFIG. 11 is a sectional view of a portion where the gas discharge port 52i is formed. As illustrated in FIGS. 10 and 11, the peripheralintroduction part 52 is sandwiched and supported between the containerupper portion 12A and the container lower portion 12B.

As a more specific example, the peripheral introduction part 52 issupported in a state where the upper surface of the first base 52 m ofthe first ring member 52 a and the lower end portion of the containerupper portion 12A are in contact with each other. A sealing member 54 dsuch as an O-ring may be provided between the upper surface of the firstbase 52 m and the lower end portion of the container upper portion 12A.For example, the sealing member 54 d is an annular member and isaccommodated in an annular groove formed on the upper surface of thefirst base 52 m. Due to the sealing member 54 d, the airtightnessbetween the first ring member 52 a and the container upper portion 12Ais secured. An electrically conductive member 55 d may be providedbetween the upper surface of the first base 52 m and the lower endportion of the container upper portion 12A. As an example, theelectrically conductive member 55 d is an annular string-like member inwhich a thin metal is spirally wound. For example, the electricallyconductive member 55 d is accommodated in an annular groove formed onthe upper surface of the first base 52 m. Due to the electricallyconductive member 55 d, the conductivity between the first ring member52 a and the container upper portion 12A is improved.

Further, the peripheral introduction part 52 is connected in a statewhere the lower surface of the second base 52 x of the second ringmember 52 b and the upper end portion of the container lower portion 12Bare in contact with each other. A sealing member 54 e such as an O-ringmay be provided between the lower surface of the second base 52 x andthe upper end portion of the container lower portion 12B. For example,the sealing member 54 e is an annular member and is accommodated in anannular groove formed in the upper end portion of the container lowerportion 12B. Due to the sealing member 54 e, the airtightness betweenthe second ring member 52 b and the container lower portion 12B issecured. An electrically conductive member 55 e may be provided betweenthe lower surface of the second base 52 x and the upper end portion ofthe container lower portion 12B. As an example, the electricallyconductive member 55 e is an annular string-like member in which a thinmetal is spirally wound. For example, the electrically conductive member55 e is accommodated in an annular groove formed in the upper endportion of the container lower portion 12B. Due to the electricallyconductive member 55 e, the conductivity between the second ring member52 b and the container lower portion 12B is improved.

In this manner, the peripheral introduction part 52 is thermally andelectrically connected to the container upper portion 12A and thecontainer lower portion 12B. The peripheral introduction part 52, thecontainer upper portion 12A, and the container lower portion 12B may beformed of the same material.

In the first ring member 52 a and the second ring member 52 b, the outersurfaces facing plasma may be coated by thermal spraying. An example ofthermal spraying metal is alumina or yttrium oxide (Y₂O₃). Further, inthe first ring member 52 a and the second ring member 52 b, the outersurfaces defining the gas flow path 52 p may be coated with acorrosion-resistant material. An example of the corrosion-resistantmaterial is an oxide of aluminum. The aluminum oxide film is formed byalumite treatment. The aluminum oxide film is formed on the inner wallof the gas flow path 52 p, whereby corrosion due to gas is suppressed.

Further, as illustrated in FIG. 11, the gas discharge port 52 i isformed to communicate with a corner portion of the cross-section of thegas flow path 52 p. The gas discharge port 52 i is open obliquely upwardfrom the upper portion on the inner side of the gas flow path 52 p. Atthe time of the alumite treatment described above, the first ring member52 a and the second ring member 52 b are put in an electrolyticsolution, and an oxide film is formed by electrolysis. At this time, airpockets tend to be formed at the corner portion of the cross-section ofthe gas flow path. In a case where the air pockets are formed at thecorner portion, the oxide film is not formed at the corner portion. Thegas discharge port 52 i is formed at the corner portion of thecross-section of the gas flow path 52 p, whereby air is easy to escape,and therefore, it is possible to prevent the air pockets from staying inthe corner portion.

FIG. 12 is a partial sectional view illustrating an example of the gasdischarge port of the peripheral introduction part. As illustrated inFIG. 12, a tip portion 52 j configuring the gas discharge port 52 i ischamfered. As an example, a radius of curvature R of the tip portion 52j is 0.5. A thermally sprayed film 56 is formed on the outer surface ofthe first ring member 52 a. The tip portion 52 j is chamfered, wherebythe thermally sprayed film 56 is also converged to be chamfered in thevicinity of the gas discharge port 52 i. In this way, the thermallysprayed film 56 is not easily peeled off. The outer surface (thermallysprayed surface) of the first ring member 52 a and the extendingdirection of the gas discharge port 52 i intersect each other at rightangle. In this way, chamfering of the tip portion 52 j can be processedinto a symmetrical shape, and the thermally sprayed film 56 is easy tobe formed and is difficult to be peeled off.

FIGS. 13 and 14 are sectional perspective views illustrating an exampleof assembly of the peripheral introduction part. FIG. 13 is a sectionalperspective view during the assembly, and FIG. 14 is a sectionalperspective view of the peripheral introduction part which has beenassembled. As illustrated in FIGS. 13 and 14, the peripheralintroduction part 52, and the container upper portion 12A and thecontainer lower portion 12B may be positioned by positioning pins.

As an example, a first pin 58 b is provided on the upper surface of thecontainer lower portion 12B. On the lower surface of the second ringmember 52 b, a hole 52 t for accommodating the first pin 58 b isprovided at a position corresponding to the first pin 58 b. The firstpin 58 b provided on the upper surface of the container lower portion12B is inserted into the hole 52 t, whereby the second ring member 52 bis positioned with respect to the container lower portion 12B. Aplurality of the first pins 58 b may be used.

As an example, a second pin 58 a is provided on the upper surface of thesecond ring member 52 b. On the lower surface of the first ring member52 a, a hole 52 s for accommodating the second pin 58 a is provided at aposition corresponding to the second pin 58 a. The second pin 58 aprovided on the upper surface of the second ring member 52 b is insertedinto the hole 52 s, whereby the first ring member 52 a is positionedwith respect to the second ring member 52 b. Further, a hole foraccommodating the second pin 58 a is provided in the lower end portionof the container upper portion 12A. In this way, the container upperportion 12A is positioned with respect to the first ring member 52 a. Aplurality of the second pins 58 a may be used. In the exampleillustrated in FIG. 8, three second pins 58 a are provided in thecircumferential direction. As illustrated in FIG. 8, the lengths of thesecond pins 58 a may be different from each other. The second pin 58 amay be fixed to the second ring member 52 b. The first pin 58 b and thesecond pin 58 a may be formed of, for example, stainless steel.

When opening the processing container 12 at the time of maintenance orthe like, the second ring member 52 b of the peripheral introductionpart 52 and the container lower portion 12B are separated from eachother. In this way, the container upper portion 12A and the peripheralintroduction part 52 are separated from the container lower portion 12B,and thus the processing container 12 is opened. That is, at the time ofthe opening and closing of the processing container 12, the containerupper portion 12A and the peripheral introduction part 52 operateintegrally.

There is a case where the sealing member 54 d disposed between thecontainer upper portion 12A and the peripheral introduction part 52 isfixed due to pressure in assembly, heat in process processing, or thelike. FIGS. 15A and 15B are sectional views for describing an example ofthe pushing screw mechanism for disconnecting the connection between thecontainer upper portion and the peripheral introduction part. FIG. 15Ais a sectional view before separation, and FIG. 15B is a sectional viewafter the separation.

As illustrated in FIG. 15A, a pushing screw mechanism 53 has a fixedblock 53 a, a support block 53 b, and a screw 53 c. The support block 53b is fixed to the side of the container upper portion 12A to face thefixed block 53 a. The support block 53 b has a screw hole extendingtoward the fixed block 53 a. The screw 53 c is screwed to a screw holeof the support block 53 b. The screw 53 c has such a length that the tipthereof can reach the fixed block 53 a. The screw 53 c is pushed in,whereby the tip of the screw 53 c butts against the fixed block 53 a andpushes the fixed block 53 a. Since the first ring member 52 a and thesecond ring member 52 b are fixed to each other by screws, the pushingscrew mechanism 53 is operated, whereby the container upper portion 12Aand the peripheral introduction part 52 can be separated from eachother, as illustrated in FIG. 15B. In this manner, by the pushing screwmechanism 53, it is possible to easily release the connection betweenthe container upper portion 12A and the peripheral introduction part 52fixed to each other by the sealing member 54 d.

Summary of Exemplary Embodiment

According to the plasma processing apparatus 10 described above, sincethe peripheral introduction part 52 is an assembly, it is possible toclean the interior of the gas flow path 52 p by releasing the couplingof at least two members forming the gas flow path 52 p. Further,according to the plasma processing apparatus 10, since the ring-shapedperipheral introduction part 52 is fixed by being sandwiched between theupper side wall 12 a and the lower side wall 12 b, it can thermallyexpand uniformly in the circumferential direction. For this reason, inthe plasma processing apparatus 10, it is possible to avoid positionalmisalignment between the axis Z passing through the center of the stage20 and the axis passing through the center of the ring-shaped peripheralintroduction part 52. Therefore, in the plasma processing apparatus 10,a decrease in the uniformity of the plasma processing due to the thermalexpansion of the peripheral introduction part 52 can be suppressed andthe maintainability of the peripheral introduction part 52 can beimproved.

According to the plasma processing apparatus 10, it is possible to openthe entire interior of the gas flow path 52 p by releasing the couplingbetween the first ring member 52 a and the second ring member 52 b.Therefore, in the plasma processing apparatus 10, the maintainabilitycan be further improved.

According to the plasma processing apparatus 10, the positioning of thecontainer upper portion 12A, the first ring member 52 a, the second ringmember 52 b, and the container lower portion 12B can be performed by thefirst pin 58 b and the second pin 58 a.

According to the plasma processing apparatus 10, the peripheralintroduction part 52, the container upper portion 12A, and the containerlower portion 12B are formed of the same material, whereby it ispossible to make the thermal expansion coefficients thereof the same.Therefore, in the plasma processing apparatus 10, the misalignmentbetween the axis Z passing through the center of the stage 20 and theaxis passing through the center of the ring-shaped peripheralintroduction part 52 due to the difference in thermal expansion betweenthe processing container 12 and the peripheral introduction part 52 canbe avoided.

According to the plasma processing apparatus 10, the gas discharge port52 i is formed at the corner portion of the cross-section of the gasflow path 52 p, whereby it is possible to prevent the air pockets fromstaying in the corner portion. In this way, the alumite treatment can beperformed uniformly.

This disclosure is not limited to the exemplary embodiment describedabove, and various modifications can be configured. For example, theplasma processing apparatus 10 is not limited to an apparatus thatexcites gas by using microwaves as a plasma source. The plasmaprocessing apparatus may have any plasma source. For example, the plasmaprocessing apparatus may be a capacitively coupled plasma processingapparatus or may be an inductively coupled plasma processing apparatus.

What is claimed is:
 1. A plasma processing apparatus comprising: aprocessing container formed by assembling a container upper portionhaving an upper side wall and a container lower portion having a lowerside wall; a stage provided in the container lower portion of theprocessing container; and a peripheral introduction part configured tobe an assembly, configured to be sandwiched between the upper side walland the lower side wall, and configured to provide a plurality of gasdischarge ports arranged in a circumferential direction with respect toan axis passing through a center of the stage, the assembly in which atleast two members are assembled, the at least two members forming a gasflow path extending in the circumferential direction with respect to theaxis in an interior thereof, wherein the peripheral introduction part,the container upper portion and the container lower portion arethermally and electrically connected to each other.
 2. The plasmaprocessing apparatus according to claim 1, wherein the at least twomembers include a first ring member and a second ring member, and thegas flow path is formed by assembling the first ring member and thesecond ring member.
 3. The plasma processing apparatus according toclaim 2, wherein the container lower portion and the second ring memberare positioned by a first pin extending along the axis, and the secondring member, the first ring member, and the container upper portion arepositioned by a second pin extending along the axis.
 4. The plasmaprocessing apparatus according to claim 1, wherein the peripheralintroduction part, the container upper portion, and the container lowerportion are formed of same material.
 5. The plasma processing apparatusaccording to claim 2, wherein the peripheral introduction part, thecontainer upper portion, and the container lower portion are formed ofsame material.
 6. The plasma processing apparatus according to claim 3,wherein the peripheral introduction part, the container upper portion,and the container lower portion are formed of same material.
 7. Theplasma processing apparatus according to claim 4, wherein the peripheralintroduction part, the container upper portion, and the container lowerportion are formed of aluminum.
 8. The plasma processing apparatusaccording to claim 5, wherein the peripheral introduction part, thecontainer upper portion, and the container lower portion are formed ofaluminum.
 9. The plasma processing apparatus according to claim 6,wherein the peripheral introduction part, the container upper portion,and the container lower portion are formed of aluminum.
 10. The plasmaprocessing apparatus according to claim 7, wherein an aluminum oxidefilm is formed on an inner wall of the gas flow path, and the pluralityof the gas discharge ports communicate with a corner portion of across-section of the gas flow path.
 11. The plasma processing apparatusaccording to claim 8, wherein an aluminum oxide film is formed on aninner wall of the gas flow path, and the plurality of the gas dischargeports communicates with a corner portion of a cross-section of the gasflow path.
 12. The plasma processing apparatus according to claim 9,wherein an aluminum oxide film is formed on an inner wall of the gasflow path, and the plurality of the gas discharge ports communicateswith a corner portion of a cross-section of the gas flow path.
 13. Theplasma processing apparatus according to claim 1, further comprising: acentral introduction part provided above the stage and configured tointroduce gas toward the stage along the axis; and an antennaintroducing microwaves into the processing container, wherein theantenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 14.The plasma processing apparatus according to claim 2, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 15.The plasma processing apparatus according to claim 3, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 16.The plasma processing apparatus according to claim 4, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 17.The plasma processing apparatus according to claim 5, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 18.The plasma processing apparatus according to claim 6, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 19.The plasma processing apparatus according to claim 7, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window. 20.The plasma processing apparatus according to claim 8, furthercomprising: a central introduction part provided above the stage andconfigured to introduce gas toward the stage along the axis; and anantenna introducing microwaves into the processing container, whereinthe antenna is provided to face the stage above the stage and has adielectric window which is in contact with a space in the processingcontainer, and a gas discharge port of the central introduction part,which extends along the axis, is formed in the dielectric window.